What Are Snow Rollers?

In Canada, a rare wind is blowing up cylindrical “snow rollers”—a phenomenon that occurs only when wind, snow, and moisture synchronize in a rare confluence of conditions.

When the wind is strong—but not too strong—and the snow is light—but not too light—and sticky, a steady wind can roll snow into neat, spiral cylinders. They dot a field of snow like icy bales of hay. They start small but can grow around two feet in diameter.

In the past few years, snow rollers have appeared in Ohio, Idaho, and Scotland. They’re most likely to be found in place with a slope, which can help the snow roll.

Snow rollers can be kind of cute as they skate across a field—but just imagine if you didn’t know anything about these and came across a field of mysterious cylinders. Aliens? Nope, just nature.